LAUSR

Coke plays an important role in a reducing agent as well as a spacer to keep permeability in the blast furnace. The role as a spacer is especially important for its efficient operation, and coke strength is desired to be high. Coke strength is known to correlate with coke pore structure,1,2) and it decreases with an increase in coke porosity.3) Also, it decreases with progress in reaction because coke matrices are consumed, and the effect of the solution loss reaction is significant.4) A decrease in coke strength in the dropping zone and in the raceway on the bottom of the blast furnace causes coke fracture and pulverization. Since the pulverized coke moves and accumulates in the center of the blast furnace and prevents stable operation, coke strength after reaction is also important. Therefore, the effect of coke reactivity and temperature history on coke strength has been investigated. Nishi et al.5) performed experiments of CO2 gasification reaction under elevated temperature conditions and evaluated coke strength after reaction using an I-type drum tester. As a result, they indicated that the amount of the consumed coke affected a decrease in coke strength because the reaction progressed in the whole coke lump Numerical Analysis of Reaction Degradation for Threedimensional Coke Pore Structure